1. Field of the Invention
This invention relates to processors and, more particularly, to techniques for organizing register files in multithreaded processors.
2. Description of the Related Art
Multithreaded processors may provide certain performance advantages over single-threaded processors. Typically, multithreaded processors may be configured to concurrently fetch, issue, and execute instructions that correspond to distinct threads of code, such as individual processes executing on a computer system. By using multithreaded execution, it may be possible to increase overall computational throughput even when executing workloads that do not exhibit significant intra-thread parallelism. For example, if a processor has two parallel execution paths that can concurrently execute instructions, then under some circumstances, two concurrently executing threads may keep those paths busier than if the processor attempted to exploit the parallelism available in a single one of the threads.
Configuring a processor for multithreaded execution may present various implementation challenges, however. For example, to avoid context-switching overhead, a multithreaded processor may be configured to implement a separate copy of architectural state (e.g., of the programmer-visible register files) for each executing thread. As the number of threads increases, the size of the circuit structures used to store such state also increases. In turn, this may result in increased processor die area, power consumption, design complexity, or other challenges.